Question

我在Tomcat服务器（V7.0.72）上运行java servlet时遇到问题。问题是Tomcat服务器提供已存在的文件，但是当我创建一个新的webapp时，它会显示“找不到文件”。

工作 examples/HelloWorld：

无效 servlets/HelloWorld：

目录结构是：

 tomcat
  |    
  +-- webapps
       |
       +- servlets
           |
           +- WEB-INF
               |
               +- classes
               |   |
               |   +- HelloWorld.class
               |   | 
               |   +- HelloWorld.java
               |    
               +- web.xml

web.xml的内容：

<?xml version="1.0" encoding="ISO-8859-1"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
                          http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
         version="3.0"
         metadata-complete="true">

    <description>
        Servlet and JSP Examples.
    </description>
    <display-name>Servlet and JSP Examples</display-name>

    <!-- Define example filters -->
    <filter>
        <filter-name>Timing filter</filter-name>
        <filter-class>filters.ExampleFilter</filter-class>
        <init-param>
            <param-name>attribute</param-name>
            <param-value>filters.ExampleFilter</param-value>
        </init-param>
    </filter>

    <filter>
        <filter-name>Request Dumper Filter</filter-name>
        <filter-class>org.apache.catalina.filters.RequestDumperFilter</filter-class>
    </filter>

    <!-- Example filter to set character encoding on each request -->
    <filter>
        <filter-name>Set Character Encoding</filter-name>
        <filter-class>org.apache.catalina.filters.SetCharacterEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>EUC_JP</param-value>
        </init-param>
        <init-param>
            <param-name>ignore</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>

    <filter>
        <filter-name>Compression Filter</filter-name>
        <filter-class>compressionFilters.CompressionFilter</filter-class>
        <init-param>
            <param-name>compressionThreshold</param-name>
            <param-value>128</param-value>
        </init-param>
        <init-param>
            <param-name>compressionBuffer</param-name>
            <param-value>8192</param-value>
        </init-param>
        <init-param>
            <param-name>compressionMimeTypes</param-name>
            <param-value>text/html,text/plain,text/xml</param-value>
        </init-param>
        <init-param>
            <param-name>debug</param-name>
            <param-value>0</param-value>
        </init-param>
    </filter>

    <!-- Define filter mappings for the timing filters -->
    <!--
    <filter-mapping>
        <filter-name>Timing Filter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
    -->

    <!-- Example filter mapping to apply the "Set Character Encoding" filter
         to *all* requests processed by this web application -->
    <!--
        <filter-mapping>
            <filter-name>Set Character Encoding</filter-name>
            <url-pattern>/*</url-pattern>
        </filter-mapping>
    -->

    <!--
        <filter-mapping>
          <filter-name>Compression Filter</filter-name>
          <url-pattern>/CompressionTest</url-pattern>
        </filter-mapping>
    -->

    <!--
        <filter-mapping>
            <filter-name>Request Dumper Filter</filter-name>
            <url-pattern>/*</url-pattern>
        </filter-mapping>
    -->

    <!-- Define example application events listeners -->
    <listener>
        <listener-class>listeners.ContextListener</listener-class>
    </listener>
    <listener>
        <listener-class>listeners.SessionListener</listener-class>
    </listener>

    <!-- Define servlets that are included in the example application -->

    <servlet>
        <servlet-name>ServletToJsp</servlet-name>
        <servlet-class>ServletToJsp</servlet-class>
    </servlet>
    <servlet>
        <servlet-name>ChatServlet</servlet-name>
        <servlet-class>chat.ChatServlet</servlet-class>
    </servlet>
    <servlet>
        <servlet-name>CompressionFilterTestServlet</servlet-name>
        <servlet-class>compressionFilters.CompressionFilterTestServlet</servlet-class>
    </servlet>
    <servlet>
        <servlet-name>HelloWorld</servlet-name>
        <servlet-class>HelloWorld</servlet-class>
    </servlet>
    <servlet>
        <servlet-name>RequestInfoExample</servlet-name>
        <servlet-class>RequestInfoExample</servlet-class>
    </servlet>
    <servlet>
        <servlet-name>RequestHeaderExample</servlet-name>
        <servlet-class>RequestHeaderExample</servlet-class>
    </servlet>
    <servlet>
        <servlet-name>RequestParamExample</servlet-name>
        <servlet-class>RequestParamExample</servlet-class>
    </servlet>
    <servlet>
        <servlet-name>CookieExample</servlet-name>
        <servlet-class>CookieExample</servlet-class>
    </servlet>
    <servlet>
        <servlet-name>SessionExample</servlet-name>
        <servlet-class>SessionExample</servlet-class>
    </servlet>

    <servlet-mapping>
        <servlet-name>ChatServlet</servlet-name>
        <url-pattern>/servlets/chat/chat</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>CompressionFilterTestServlet</servlet-name>
        <url-pattern>/CompressionTest</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>HelloWorld</servlet-name>
        <url-pattern>/HelloWorld</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>RequestInfoExample</servlet-name>
        <url-pattern>/servlets/servlet/RequestInfoExample/*</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>RequestHeaderExample</servlet-name>
        <url-pattern>/servlets/servlet/RequestHeaderExample</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>RequestParamExample</servlet-name>
        <url-pattern>/servlets/servlet/RequestParamExample</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>CookieExample</servlet-name>
        <url-pattern>/servlets/servlet/CookieExample</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>SessionExample</servlet-name>
        <url-pattern>/servlets/servlet/SessionExample</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>ServletToJsp</servlet-name>
        <url-pattern>/servletToJsp</url-pattern>
    </servlet-mapping>

    <jsp-config>
        <taglib>
            <taglib-uri>
                http://tomcat.apache.org/debug-taglib
            </taglib-uri>
            <taglib-location>
                /WEB-INF/jsp/debug-taglib.tld
            </taglib-location>
        </taglib>

        <taglib>
            <taglib-uri>
                http://tomcat.apache.org/example-taglib
            </taglib-uri>
            <taglib-location>
                /WEB-INF/jsp/example-taglib.tld
            </taglib-location>
        </taglib>

        <taglib>
            <taglib-uri>
                http://tomcat.apache.org/jsp2-example-taglib
            </taglib-uri>
            <taglib-location>
                /WEB-INF/jsp2/jsp2-example-taglib.tld
            </taglib-location>
        </taglib>

        <jsp-property-group>
            <description>
                Special property group for JSP Configuration JSP example.
            </description>
            <display-name>JSPConfiguration</display-name>
            <url-pattern>/jsp/jsp2/misc/config.jsp</url-pattern>
            <el-ignored>true</el-ignored>
            <page-encoding>ISO-8859-1</page-encoding>
            <scripting-invalid>true</scripting-invalid>
            <include-prelude>/jsp/jsp2/misc/prelude.jspf</include-prelude>
            <include-coda>/jsp/jsp2/misc/coda.jspf</include-coda>
        </jsp-property-group>
    </jsp-config>

    <security-constraint>
        <display-name>Example Security Constraint</display-name>
        <web-resource-collection>
            <web-resource-name>Protected Area</web-resource-name>
            <!-- Define the context-relative URL(s) to be protected -->
            <url-pattern>/jsp/security/protected/*</url-pattern>
            <!-- If you list http methods, only those methods are protected -->
            <http-method>DELETE</http-method>
            <http-method>GET</http-method>
            <http-method>POST</http-method>
            <http-method>PUT</http-method>
        </web-resource-collection>
        <auth-constraint>
            <!-- Anyone with one of the listed roles may access this area -->
            <role-name>tomcat</role-name>
            <role-name>role1</role-name>
        </auth-constraint>
    </security-constraint>

    <!-- Default login configuration uses form-based authentication -->
    <login-config>
        <auth-method>FORM</auth-method>
        <realm-name>Example Form-Based Authentication Area</realm-name>
        <form-login-config>
            <form-login-page>/jsp/security/protected/login.jsp</form-login-page>
            <form-error-page>/jsp/security/protected/error.jsp</form-error-page>
        </form-login-config>
    </login-config>

    <!-- Security roles referenced by this web application -->
    <security-role>
        <role-name>role1</role-name>
    </security-role>
    <security-role>
        <role-name>tomcat</role-name>
    </security-role>

    <!-- Environment entry examples -->
    <!--env-entry>
      <env-entry-description>
         The maximum number of tax exemptions allowed to be set.
      </env-entry-description>
      <env-entry-name>maxExemptions</env-entry-name>
      <env-entry-type>java.lang.Integer</env-entry-type>
      <env-entry-value>15</env-entry-value>
    </env-entry-->
    <env-entry>
        <env-entry-name>minExemptions</env-entry-name>
        <env-entry-type>java.lang.Integer</env-entry-type>
        <env-entry-value>1</env-entry-value>
    </env-entry>
    <env-entry>
        <env-entry-name>foo/name1</env-entry-name>
        <env-entry-type>java.lang.String</env-entry-type>
        <env-entry-value>value1</env-entry-value>
    </env-entry>
    <env-entry>
        <env-entry-name>foo/bar/name2</env-entry-name>
        <env-entry-type>java.lang.Boolean</env-entry-type>
        <env-entry-value>true</env-entry-value>
    </env-entry>
    <env-entry>
        <env-entry-name>name3</env-entry-name>
        <env-entry-type>java.lang.Integer</env-entry-type>
        <env-entry-value>1</env-entry-value>
    </env-entry>
    <env-entry>
        <env-entry-name>foo/name4</env-entry-name>
        <env-entry-type>java.lang.Integer</env-entry-type>
        <env-entry-value>10</env-entry-value>
    </env-entry>

    <!-- Async examples -->
    <servlet>
        <servlet-name>async0</servlet-name>
        <servlet-class>async.Async0</servlet-class>
        <async-supported>true</async-supported>
    </servlet>
    <servlet-mapping>
        <servlet-name>async0</servlet-name>
        <url-pattern>/async/async0</url-pattern>
    </servlet-mapping>
    <servlet>
        <servlet-name>async1</servlet-name>
        <servlet-class>async.Async1</servlet-class>
        <async-supported>true</async-supported>
    </servlet>
    <servlet-mapping>
        <servlet-name>async1</servlet-name>
        <url-pattern>/async/async1</url-pattern>
    </servlet-mapping>
    <servlet>
        <servlet-name>async2</servlet-name>
        <servlet-class>async.Async2</servlet-class>
        <async-supported>true</async-supported>
    </servlet>
    <servlet-mapping>
        <servlet-name>async2</servlet-name>
        <url-pattern>/async/async2</url-pattern>
    </servlet-mapping>
    <servlet>
        <servlet-name>async3</servlet-name>
        <servlet-class>async.Async3</servlet-class>
        <async-supported>true</async-supported>
    </servlet>
    <servlet-mapping>
        <servlet-name>async3</servlet-name>
        <url-pattern>/async/async3</url-pattern>
    </servlet-mapping>
    <servlet>
        <servlet-name>stock</servlet-name>
        <servlet-class>async.AsyncStockServlet</servlet-class>
        <async-supported>true</async-supported>
    </servlet>
    <servlet-mapping>
        <servlet-name>stock</servlet-name>
        <url-pattern>/async/stockticker</url-pattern>
    </servlet-mapping>

    <!-- WebSocket Examples using Deprecated Tomcat 7 API-->
    <servlet>
        <servlet-name>wsEchoStream</servlet-name>
        <servlet-class>websocket.tc7.echo.EchoStream</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>wsEchoStream</servlet-name>
        <url-pattern>/websocket/tc7/echoStream</url-pattern>
    </servlet-mapping>
    <servlet>
        <servlet-name>wsEchoMessage</servlet-name>
        <servlet-class>websocket.tc7.echo.EchoMessage</servlet-class>
        <!-- Uncomment the following block to increase the default maximum
             WebSocket buffer size from 2MB to 20MB which is required for the
             Autobahn test suite to pass fully. -->
        <!--
        <init-param>
          <param-name>byteBufferMaxSize</param-name>
          <param-value>20971520</param-value>
        </init-param>
        <init-param>
          <param-name>charBufferMaxSize</param-name>
          <param-value>20971520</param-value>
        </init-param>
        -->
    </servlet>
    <servlet-mapping>
        <servlet-name>wsEchoMessage</servlet-name>
        <url-pattern>/websocket/tc7/echoMessage</url-pattern>
    </servlet-mapping>
    <servlet>
        <servlet-name>wsChat</servlet-name>
        <servlet-class>websocket.tc7.chat.ChatWebSocketServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>wsChat</servlet-name>
        <url-pattern>/websocket/tc7/chat</url-pattern>
    </servlet-mapping>
    <servlet>
        <servlet-name>wsSnake</servlet-name>
        <servlet-class>websocket.tc7.snake.SnakeWebSocketServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>wsSnake</servlet-name>
        <url-pattern>/websocket/tc7/snake</url-pattern>
    </servlet-mapping>
    <!-- Websocket examples -->
    <listener>
        <listener-class>websocket.drawboard.DrawboardContextListener</listener-class>
    </listener>

    <welcome-file-list>
        <welcome-file>index.html</welcome-file>
        <welcome-file>index.xhtml</welcome-file>
        <welcome-file>index.htm</welcome-file>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>

</web-app>

HelloWorld.java的内容：

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ResourceBundle;

public class HelloWorld extends HttpServlet {

    private static final long serialVersionUID = 1L;

    @Override
    public void doGet(HttpServletRequest request,
                      HttpServletResponse response)
            throws IOException, ServletException {
        ResourceBundle rb =
                ResourceBundle.getBundle("LocalStrings", request.getLocale());
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();

        out.println("<html>");
        out.println("<head>");

        String title = rb.getString("helloworld.title");

        out.println("<title>" + title + "</title>");
        out.println("</head>");
        out.println("<body bgcolor=\"white\">");

        // note that all links are created to be relative. this
        // ensures that we can move the web application that this
        // servlet belongs to to a different place in the url
        // tree and not have any harmful side effects.

        // XXX
        // making these absolute till we work out the
        // addition of a PathInfo issue

        out.println("<a href=\"../helloworld.html\">");
        out.println("<img src=\"../images/code.gif\" height=24 " +
                "width=24 align=right border=0 alt=\"view code\"></a>");
        out.println("<a href=\"../index.html\">");
        out.println("<img src=\"../images/return.gif\" height=24 " +
                "width=24 align=right border=0 alt=\"return\"></a>");
        out.println("<h1>" + title + "</h1>");
        out.println("</body>");
        out.println("</html>");
    }
}

欢迎任何建议。谢谢。

Answer 1

我不确定你在哪里获得了这个web.xml但是我鼓励你从小做起 - 很难理解那里有什么。让您的生活变得轻松，并从以下内容开始：

<?xml version="1.0" encoding="ISO-8859-1"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
                          http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
         version="3.0"
         metadata-complete="true">

    <servlet>
        <servlet-name>hello</servlet-name>
        <servlet-class>HelloWorld</servlet-class>
    </servlet>

    <servlet-mapping>
        <servlet-name>hello</servlet-name>
        <url-pattern>/hello</url-pattern>
    </servlet-mapping>
</web-app>

根据需要，您可以添加过滤器等。

顺便说一句，如果你不想要它，你甚至不再需要web.xml。您可以将servlet更改为以下内容：

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet(urlPatterns = {"/hello"})
public class HelloWorld extends HttpServlet {

代替。这会将servlet映射到Web应用程序中的/ hello，与web.xml相同。

Tomcat服务器上的Java Servlet（找不到文件错误）

1 个答案: